Cheung was born in Hong Kong in 1950. He graduated from the University of Hong Kong in 1972, then became an Information Officer for the then British colonial government. During the Vietnamese refugee crisis of the 1970s, he was responsible for arranging visits for foreign media to the refugee camps.[1] He was transferred to the Administrative Service in September 1979 and has served in various bureaus and departments in the government.

During his earlier years of service, he served in the Finance Branch, Home Affairs Department, City and New Territories Administration, Government House and the Industry Department. As a directorate officer since 1986, Cheung served as District Officer of North District, Assistant Director-General of Trade, Administrative Assistant to the Financial Secretary, Deputy Judiciary Administrator, and Deputy Head of Central Policy Unit.[2]

He was promoted to Deputy Secretary for Education and Manpower (1996–1999), Commissioner for Labour (1999–2000), Director of Education (2000–2002), and Permanent Secretary for Economic Development and Labour (later known as Permanent Secretary for Economic Development/Commissioner for Labour; 2002–2007). He was promoted to Administrative Officer Staff Grade A1 in September 2004.[2] Cheung was known for his hardworking style, having taken less than three weeks off in the five years leading up to his retirement in March 2007 as Permanent Secretary for Economic Development and Labour.[1]

In July 2007, he was appointed Secretary for Labour and Welfare, one of the principal officials. During his tenure, he oversaw the minimum wage legislation and Work Incentive Transport Subsidy Scheme introduced in 2011. He also tackled issues such as the Old Age Living Allowance, standard working hours and paternity leave, all of which are still fiercely debated over by unionists and employers with opposing views.[1] He was criticised for his low profile during the 2013 Hong Kong dock strike.[3] He was also criticised for only taking orders from his superiors and not taking responsibility for decisions.[1]